Howdy all, I'm knee deep in replacing bearings and whatever else in my '81 5 speed tranny.
I'm up to removing the shift mechanism. When I start to undo the two bolts on the front of the tranny, they are not screwing out.
Instead, it appears that the shift mechanism is moving rearward as the bolts undo. I can see this leading to potential disaster.
I haven't undone the bolts more than two turns but I can clearly see that the bolts are not coming out.

ME109, I just checked my disassembled 5 speed and in my case one bolt will go into one hole easily the second bolt wont go in either hole which tells me it must be a tight fit. I can feel some dried grease or sealer build up on the bolt shanks. It has been disassembled for years.

Heat the housing around the bolts and they should come out easily. The aluminum will expand faster then the steel bolts.

Unscrew one bolt with the other holding the shift mechanism in place. The one bolt will come out. Don't remove it all the way, put it back in./ Unscrew the two bolt with the one bolt holding the shift mechanism in place. Now that both are loose remove the bolts.

Unscrew one bolt with the other holding the shift mechanism in place. The one bolt will come out. Don't remove it all the way, put it back in./ Unscrew the two bolt with the one bolt holding the shift mechanism in place. Now that both are loose remove the bolts.

I considered doing it that way but thought there may be a chance of snapping the 'alloy frame'.

They fit tight so the shifter won't walk and the oil won't leak. I just back the shifter off evenly and then get the bolts out however. Tap the ends if need be. I think I usually back them out with an air ratchet.

The one shifter cam has a gear attatched to it. The gear often works loose from the cam. It causes notchy shifting.

They fit tight so the shifter won't walk and the oil won't leak. I just back the shifter off evenly and then get the bolts out however. Tap the ends if need be. I think I usually back them out with an air ratchet.

The one shifter cam has a gear attatched to it. The gear often works loose from the cam. It causes notchy shifting.

I think I'm with you now on the shifter cam now.

The problem I saw with forging ahead undoing the bolts was that the shifter forks are hooked up in the shifter mechanism and could be damaged if not disconnected from the mechanism, so to speak.

I think I just pull the shifter forks' shaft out first. I really don't remember for sure. There's a couple of different ways to do it and not get into any trouble. It sounds like you are aware that there are even more ways to get into trouble. Good luck!

I heated the housing around one bolt, undid the bolt while leaving the other one tight (Thanks disston)
Then heated the casing around the remaining bolt and undid it a couple of turns, then tapped the mechanism back into place and repeated until the mechanism came free.

I was able to pull the double shift fork shaft enough to get it out of the way, but the single fork shaft stayed put.